#6 #999

soft1614080902427/Soft1614080902427Activity.java

@@ -2,6 +2,6 @@
 
 public class Soft1614080902427Activity{
   public static void main(String[] args){
-    System.out.println("Hello World!");
+    System.out.println("Hello World!123");
   }
 }

soft1614080902427/java/edu/hzuapps/androidlabs/soft1614080902427/Downloader.java

@@ -0,0 +1,79 @@
+package edu.hzuapps.androidlabs.soft1614080902427;
+
+import android.os.AsyncTask;
+import android.util.Log;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
+import java.io.Reader;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+
+
+public class Downloader {
+    private final static String TAG = Downloader.class.getSimpleName();
+
+    private final DownloaderListener listener;
+
+    public Downloader(DownloaderListener listener) {
+        this.listener = listener;
+    }
+
+    public void createTask(String url) {
+
+        new AsyncTask<String, Integer, ByteArrayOutputStream>() {
+            public String url;
+
+            @Override
+            protected ByteArrayOutputStream doInBackground(String[] params) {
+                this.url = params[0];
+
+                HttpURLConnection connection = null;
+                InputStream is = null;
+                ByteArrayOutputStream out = null;
+                try {
+                    connection = (HttpURLConnection) new URL(this.url).openConnection();
+                    is = connection.getInputStream();
+                    out = new ByteArrayOutputStream();
+                    byte[] buffer = new byte[256];
+                    int bytesRead;
+                    while((bytesRead = is.read(buffer))!=-1){
+                        out.write(buffer,0,bytesRead);
+                    }
+                } catch (Exception e) {
+                    Log.e(TAG,"下载 " +url + "出现错误: "+e.toString());
+                }
+                return out;
+            }
+
+            @Override
+            protected void onPreExecute() {
+                super.onPreExecute();
+            }
+
+            @Override
+            protected void onPostExecute(ByteArrayOutputStream stream) {
+                super.onPostExecute(stream);
+                Downloader.this.listener.onDone(this.url, stream);
+            }
+
+            @Override
+            protected void onProgressUpdate(Integer... values) {
+                super.onProgressUpdate(values);
+            }
+
+            @Override
+            protected void onCancelled(ByteArrayOutputStream stream) {
+                super.onCancelled(stream);
+                listener.onError(this.url);
+            }
+
+        }.execute(url);
+    }
+}

soft1614080902427/java/edu/hzuapps/androidlabs/soft1614080902427/DownloaderListener.java

@@ -0,0 +1,17 @@
+package edu.hzuapps.androidlabs.soft1614080902427;
+
+import java.io.ByteArrayOutputStream;
+import java.io.OutputStream;
+
+public abstract class DownloaderListener {
+    public DownloaderListener() {
+    }
+
+    public void onError(String url) {
+
+    }
+
+    public void onDone(String url, ByteArrayOutputStream stream) {
+
+    }
+}